• To find the factors that significantly affected prognosis in patients with peripheral arterial thromboembolism, we reviewed a 12-year experience at two hospitals. Sixty-one patients had 67 embolectomies. Operative treatment and management preserved the limbs in 75.8%. Mortality was 22.4%. Outcome was favorably affected when age was less than 60 years and when arteriosclerotic heart disease was absent, and was adversely affected when common femoral emboli were present and heamtocrit level elevated. Duration of symptoms did not affect outcome. Our treatment of patients with peripheral embolism is based on the effect of certain intrinsic factors on the formation of distal thrombus. These factors may be more important than duration of symptoms. Immediate, complete heparinization is recommended to arrest thrombosis, and to allow both for proper emphasis on treatment of the often-associated cardiopathy and for attention to hydration and acid-base balance. This preoperative plan of therapy should produce maximal limb salvage with reduced operative mortality.